Threading apparatus



Feb. 19, 1952 Q LAEMMEL 2,586,668

THREADING APPARATUS Filed April 29, 1948 INVENToR. Aa/b5@ HM PatentedFeb. 19, 1952 THREADING'" APPARATUS Charles H. Laemmel, Detroit, Mich.,assignor, by

mesne assignments, to The Shelield Corporation, Dayton, Ohio, acorporation of Ohio Application April 29, i948, serial No. 23,999

2 claims. (ci. 10-95) This invention relates to thread cutting tools.

One object of the invention is the provision of a threading head havingimproved means for controlling the operation of a tool adjusting sleevewith respect to the holder in which the threading cutters are arranged,the construction being such that the sleeve is adjustable by a leverrotatable on a radial axis and having an eccentric pin operable in atransverse groove in the cutter holder which is also provided with alongitudinally extending pin receiving groove that permits retraction ofthe sleeve beyond its normal operating range in order that the threadingcutters can be released and removed.

Y A further object of the invention is the provision of a threading diehead' having a control lever operable about an axis extending radiallyof the head and held against other than rotational movement, the leverbeing arranged for rotation beyond its normal opening and closingrangeof movement to permit retraction of the chaser adjusting'sleeve tosuch an extent `that the chasers can be removed from the holder.

Other objects and advantages of the invention will be apparent from thefollowing description, the appended claims and the accompanying drawing,in which:

Fig.` 1 is an end view of a threading head embodying the presentinvention; Y Y

Fig. 2 is a longitudinal section on the line 2-2 of Fig. 1;

Fig. 3 is a longitudinal section on an enlarged scale on the line 3-3 ofFig. 1;

Fig. 4 is a top plan view of the threading head showing the sleeveretracted to permit release of the chasers; and

Fig. 5 is a section on the line 5-5 of Fig. 3 and showing a portion ofthe holding plate.

vReferring more particularly to the drawing in which the preferredembodiment of the invention has been illustrated in its association witha self-opening threading die head having radial thread chasers, Igenerally designates a chaser holding body having suitable slotssupporting the chasers or tools II for radial sliding movement therein.Coil springs I 2 acting on pins I3 carried by the chasers urge thechasers outwardly from the closed or threading position represented inFig. 2 in the same manner as in the patent to France 1,777,380. Anvadjusting sleeve I is axially movable on the body `I0 to open orrelease the chasers as in the patent just mentioned.

The body I0 preferably comprises a forward section I6 and a rearsectionI1 xed to one another by suitable bolts, not shown, section I1 beingslidably carried on the shaft I8` and urged Fig. 3, by means of springs20. The left hand ends of springs 20 are received. in recesses-in aagainst which the end of the body portion I1 engages. part ofthe bodyportion I1 secures a threaded adjusting collar 23 in desired position sothat when the relative axial movement of the Work and the threading headis stopped during a threading operation, the continued rotation of oneof those parts draws the threading head forwardly against the action ofsprings to a predetermined point when the sleeve I 5 is moved to theright and the `dies are automatically opened by trip means of thecharacter shown f sleeve so that the shaft can rotate about an axisextending radially of the threading head. Projecting laterally from .theshaft 25 is an operating arm 21 which can be moved from a closed orthreading position shown at A in Fig. 4 to an open position indicated atB. The handle swings in a plane tangential to and above the die head sothat pressure can very conveniently l be applied Yby the operator inclosing the die head. The shaft 25 is. operably connected to the toolcarrying body I 0 by means of a projecting pin 29 which is at, one sideof the shaft axis. This pin operates in a transverse groove 30 in thebody and the axial components of the pins movements are effective toclose the die when the handle 21 is moved from the position B toposition A indicated in Fig. 4. When the head is automatically opened atthe end of a threading operation, the handle swings back to sleeve I5 asby means ofla screw 32.

position B as the sleeve I5 is moved rearwardly.

The shaft 25' is positively held against axial movement, whilepermitting its free rotation, by means of a holding plate 3| secured tothe The two legs 33 of this plate enter opposed transverse slots 34 inthe bushing 26 to fix the bushing against axial and rotational movementin the sleeve I5, legs 33 also entering the opposite sides of an annulargroove 35 inthe shaft 25 to permit rotation of the shaft kwhile holdingit in place against axial movement.

The swinging movements of the arm 21 are preferably limited in apositive manner by a stop o pin 36 on shaft '25 which engages a shoulder31 towards the right on the shaft as viewed in i on the bushing 2B whenthe handle 21 swings towards the right some little distance beyond theposition B shown in Fig. 4 but before it reaches a position in line withthe shaft I 8.

In accordance with the present inventionthe handle 21 may be swungbeyond its normal oper- YLock nut,22 threaded on the rear ating range ifthe operator .so desires, in order that the sleeve I may be movedtowards the right far enough to entirely release the threading dies Ilfrom the body I0, Without requiring the use of tools or disassemblingany of the parts of the threading head. As previously mentioned, thestop pin 36 normally prevents this movement but pin 36 may, if desired,be intentionally depressed by the operator to permit continued travel ofthe arm 2l. For this purpose the pin 36 is slidably carried in a radialbore and held in its normal projected position by means of a spring Wire39 arrangedin an annular groove 46 in the shaft 25, the end of thisspring pressing against a head 4l on the pin to normally hold the pinprojected but permitting the pin tok be moved back far enough so that itno longer engages the shoulder 31. The operator can thus move the handleto the position C shown in full lines in Fig. 4. pin 29 on shaft 25 ismoved to a position in line with an axially extending slot 43 in thebody Hl and this permits the sleeve l5 to be moved towards the right asviewed in the drawing to the position shown in Fig. 4 in which the endsof the slots that carry the chasers are entirely uncovered so that thechasers can be moved for resharpening or inspection, Without requiringthe use of tools and Without requiring the disassembling of any of theparts one from another. Complete disassembly of the sleeve i5 from thebody can be effected by unscrewing the nut 2|.

In this position the projecting When it is desired to close thethreading head after reinserting the chasers, it is merely necessary toenter the pin'29 in the longitudinal slot until the pin 29 is inthetransverse slot 3B. The

handle 2 can then be swung 'clockwise' to the position B and then on topositionl A which Will Y.

close the die head. Before the handle reaches theposition B in movingfrom position C, the stop pin 36 will be uncovered and released so itmay spring out to its normalposition again from the retracted positionin which it is held bythe upper portion of the bushing 26.

vAs will now be'apparent,l the rotational movements of the shaft movethe pin only in the transverse slot'SD during the normal operating rangebetween. opening and closing position and it is only when the handle isrotated to a position beyond the normal operating range that pin 2Q canenter the longitudinal slot 43 and permit full retraction of the sleeveon the body to release the dies. In accordance with this invention, itwill be clear, since the handle swings in a plane which is tangential ofthe threading head, that the required power can be conveniently 'appliedeven in dies of considerable size.

While the form of apparatus herein described constitutes a preferredembodiment of the invention, it is to be understoodthat the invention isnot limited to this precise form of apparatus,Y and that changes may bemade therein Without `departing from the scope of the invention which isdened in the appended claims, t

What is claimed is:

l. A self-opening threading head comprisin a body provided with meansfor guiding'threading tools foropening and closing movements, aY sleeveaxially movableon said body through a normal operating range fromopening to closing pos1t1on of the tools, a rotatable ShaftprOVided Witha handle and an operating pin eccentric' .oi the shaft axis, vmeans onsaid sleevellqatbly.

-axis extending radiallyoffthe sleeve, means re taining said rotatablepin mounting shaft against movement along its axis, said body on itsperipheral portion having a transverse groove receiving said pin so thatthe axial component of rotational movement of the pin in its normaloperating range causes axial movement of the sleeve on the body, saidbody also having a pin receiving groove extending substantially axiallyof the body from a point on said transverse groove which issubstantially beyond the pins normal operating range of movement, thebottom of the axial pin receiving groove lying inwardly of the geometricplane in which the bottom of the pin moves during normal operation tocause axial ino-vejment of the sleeve, the size relationship of saidshaft, pin and transverse and axial grooves being such that the pin ismovable from the transverse groove to the axial groove by rotation ofthe shaft beyond the limit of its normal operating range whereby thesleeve is retracted beyond its normal operating range of movement torelease the threading tools when the pin is moved to a point on thetransverse groove substantially beyond the pins normal operating rangeof move ment.

2. A vself-opening threading head comprising a body provided with meansfor guiding threading tools for opening and closing movements, a sleeveaxially movable on said body through a normal operating range fromopening to closing position of vthe tools, a rotatable shaft providedWith a handle and an operating pin eccentric of the shaft axis, means onsaid sleeve rotatably supporting said shaft for movement about an axisextending radially of the sleeve, means positively retaining saidrotatable pin mounting shaft against movement along its axis, manuallyreleasable means positively stopping rotation of the shaft beyond anormal operating range, said body in its peripheral portion having atransverse groove receiving said pin so that the axial component ofrotational movement of the pin inits normal operating range causes axialmoved ment of the sleeve on the body, said body also having a pinreceiving groove extending 'substan-l tially axially of the'body from apoint on said transverse groove vwhich is substantially beyond the pinsnormal operating range of movement, the bottom ofthe axial pin receivinggroove lying inwardly ofthe geometric plane in which theV bottom of thepin moves during normal operation to cause` axial movement of thesleeve, the size relationship of said shaft, pin and transverse andaxial groovesbeing such that the pin is movable from the transversegroove to theaxial grooveV by rotation of thesh'aft beyond the limit ofits normal operating range whereby the sleeve is retracted 'beyond itsnormal operating range of movement to release the .threading tools whenthe pin'is moved to a point onY the transverse groove substantiallybeyond the pins normal operating range of movement.

` CHARLES H. LAEMMEL.

REFERENCES CITED The vfollowing `references are of record in the le ofthis patent: l

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